Dual voltage switching device



Dec. 15, 1953 H KEITH 2,663,000

' DUAL VOLTAGE SWITCHING DEVICE Filed Jan. 2, 1952 2 Sheets-Sheet l 2 3 I 2 3 I Fig.8 v Fig. 9 f j m FIgJO Fig.1!

Huber! Lee Keith INVEN TOR.

g9 g9 7 9 a 7' BY 3,

w mm Dec. 15, 1953 H. KEITH 2,663,000

DUAL VOLTAGE SWITCHING DEVICE Filed Jan. 2, 1952 2 Sheets-Sheet 2 Fig.5

Hubert Lee Keith INVENTOR.

Patented Dec. 15, 1953 UNITED STATES harem OFFICE 2 Claims.

This invention relates to a dual voltage switching device and particularly to a switching device to be attached to the leads of a standard twovoltage, three-phase motor for selecting the connections of the motor to operate at either of the two normal voltages.

Most portable electric motor-driven machinery such as contractors hoists, air compressors, pumps, etc. use three-phase alternating current motors as the power plant for the devices. Because of the arrangement of the electrical dis tribution systems it is found that at some locations 220 volt, three-phase power is available and at others 440 volt, three-phase power is available.

For this reason, and for many others, standard motors of the three-phase type have been constructed to operate on either 22c or 440 volts, the so-called standard dual voltage motors. The National Electric Manufacturers Association has standardized such connections so that all makers of such dual voltage motors have identical terminal facilities. The various end terminals of the windings are brought out to a terminal box and the terminals are provided with standard numbers according to the N. E. M. A. standards. When it is desired to use one of these dual voltage motors at any one of the described voltages it is necessary to remove the cover plate from the motor and to connect the terminals according to the standard N. E. M. A. diagram. Such connection requires skilled labor to make the proper connection and to properly tape and insulate the same so that it will operate over long periods of time or under all stresses that the motor may be subject to without short circuiting or otherwise disturbing the motor.

The standard dual voltage motors of the threephase type may be either Y-connected or socalled star connected or they may be delta connected or so-called polygon connection. In either event, the motor windings will be built in a plurality of sections, usually two, with the terminals brought out and labeled as per the N. E. M. A. specifications. Any skilled electrician knowing the N. M. A. diagrams may safely connect the proper terminals together it being necessary only to know whether the motor is Y or delta connected. Dual voltage motors usually come with wiring diagram plates attached, showing the proper .grouping of the terminals for the "voltage desired.

.It is also customary to use a'l-ine switch or a main line breaker with such a motor and to provide the breaker or line switch with a dual voltage holding coil. That is, the holding coil is divided into two sections and may be connected either in parallel or in series depending on the voltage to be handled.

The present invention provides a switch arrangement to be permanently connected to the nine terminals of such a standard dual voltage motor and to the four terminals of such a standard dual voltage line switch and provide connections so that a simple single movement of the switching device will connect either for the low voltage or the high voltage use.

The switch device is likewise provided with an auxiliary set of terminals so that the same motions can be utilized with either a delta or a Y-connected machine with the only difierence being that three of the terminals are connected to different sets of terminals in the switching device for the Y and delta machines.

The switching device according to this invention comprises a switch base having a plurality of terminals arranged in a predetermined pattern thereon for connection to the terminals of the split windings of the motor and the split coil windings of the line switch. A switch plate cooperating with the switch base has terminals which are connected together so that the plate may be selectively positioned with respect to the base to connect together certain terminals in the base so that the windings in the motor and in the line switch may be connected in either the parallel or series relation as is desirable because of the voltage at which the motor is to be operated.

It is accordingly an object of this invention to provide an improved dual voltage switching device.

It is a further object of this invention to provide a switching device capable of a single motion of connecting the split windings of a standard dual voltage motor in either of the voltage positions.

It is a further object of this invention to provide a dual voltage switch which may be connected to either a delta or a Y-connectedmotor.

It is a further object of this invention to provide a dual voltage arrangement in which the voltage may be changed without the necessity of opening the motor terminal box and making any arrangement therein.

It is another object of the invention to provide a two-position switch for connecting a dual voltage motor in either of its dual voltages.

Further objects and many of the attendant advantages of this invention will be apparent from U the following detailed description taken in conjunction with the accompanying drawings in which:

Figure 1 is a top plan View of a dual voltage switch according to the invention;

Figure 2 is a top plan view of the base of the dual voltage switch showing the pattern of the arranged terminal contacts therein;

Figure 3 is a bottom plan view of the switch plate showing the arrangements of the contacts therein and the arrangement of the connections between certain of the contacts;

Figure 4 is a vertical section through the control switch and taken along the line 4-4 of Figure l Figure 5 is a diagrammatic view of a standard dual voltage motor and switch with the changeover dual voltage switching device connected thereto;

Figure 6 is a top plan view of the switch plate in the standard low voltage position, with the contacts and connectors thereto shown as if the top of the switch were transparent;

Figure 7 is a view similar to Figure 6 showing the switch located in high voltage position with the same transparent efiect;

Figure 8 is a standard N. E. M. A. connection diagram for connecting a standard dual voltage Y connected motor in low voltage or parallel arrangement;

Figure 9 is a similar N. E. M. A. diagram of a Y-connected motor with the terminals connected in high voltage or series arrangement;

Figure 10 is a standard N. E. M. A. wiring diagram for a delta connected motor showing the terminals connected in low voltage or parallel arrangement; and,

Figure 11 is a similar standard N. E. M. A. connecting diagram showing the terminals of a delta connected dual voltage motor connected in high voltage or series arrangement.

In the exemplary embodiment of the invention, a standard dual voltage motor I9 is provided with a terminal box I2 in which are brought out the standard nine terminals of a standard dual voltage motor. The standard terminals I9 are numbered I to 9 according to the standard N. E. M. A. specification. A standard circuit breaker or line switch It is connected in the supply line 13 supplying three-phase power at either 220 or 440 volts to the standard dual voltage motor H9. The breaker I6 is provided with a plurality of contact blades 29 for closing the phases of the line I8. A dual voltage closing coil 22 is provided with two sections 22a and 221), the standard terminals of the coil 22 being numbered 10 and for one section of the coil and 2c and for the other section of the coil, the coil normally being energized by means of a starter switch not shown through the normally closed contacts 24 and 29 of the breaker l6. All of this arrangement is standard practice and is in no wise part of this invention.

Instead of providing connections within the terminal box I2 each time the motor is to be utilized for a different voltage the present invention provides a switching device 39 which includes a base 32 which is preferably provided as an annular base plate although obviously it can be of any size and shape. A switch plate 39 is pivotally mounted on a stud 39 which is anchored in the base 32. A nut or fastener 38 is applied to the stud 36 and a spring d9 is applied between the nut and the cover 34 for maintaining the cover 3 in firm contact with the base 32. The

4 base is provided with shoulders 92 and 26 to receive a handle 2-6 which is rigidly secured to the cover plate 34 and limits its oscillatory motion about the stud 96 so that the switch may assume either of two positions with the handle 46 against either the shoulder 42 or the shoulder 44.

The switch base 32 is provided with a plurality of contacts for connection to the terminals I to 9 and for convenience in following the connection the small numerals I to 9 have been applied to these contacts as well as the reference numerals 59 to '12. The reference numerals 59, 52 and 54 relate to the contacts connected to the motor terminals I, 2 and 3 which are the line or outside terminals of the split windings. The terminals 56, E9 and 69 are connected to the terminals 7, 8 and 9 of the motor windings which represent the outside of the second split winding. The contacts 62, E4 and B9 are connected to the terminals d, E and 6 of the motor I9 when the motor I9 is of the Y or star connected type. The switch plate 32 is likewise provided with alternate terminals 98, i9 and T2 to which the terminals fl, 5 and 6 are connected when the motor I9 is of the delta connected type.

The base 32 is likewise provided with four terminals 72, i9, i9 and 89 to which the terminals Ic, 3c, 20 and 4c of the split coil 22 are connected. For purposes of convenience in following the connections the designations Ic to do have likewise been applied to the terminals it to 99.

While obviously the contacts 50 to could be placed in any number of patterns a convenient and preferable pattern places each of the groups of terminals in a straight line and since this is a rotary selector, as shown, the straight lines are made radial with respect to the pivot point 39. The outside terminals 59 to 55 are arranged in a single line while the terminals 56 to 60 are likewise arranged in a separate straight line and the terminals 62 to 66 in still another straight line while the auxiliary terminals are arranged in an auxiliary straight line. The terminals 14 to 89 of the holding or actuating coil 22 are likewise arranged in a straight line but separated from the contacts 59 to I2 for reasons which will be obvious.

A cover plate 96 is likewise provided with a plurality of contacts 86 to I22. The contacts 82, 89 and 89 are arranged in a straight line group which is radial with the pivot point 96 and the contacts 88, 90 and 92 are likewise a straight line radial group. The contacts 94, 95 and 98 provide still another straight line group while the contacts ilill, I02 and I02 form a straight line group between the groups 88, to 92 and 94 to 98 while an auxiliary group I99 to H0 is placed intermediate between the groups 82 to 86 and 88 to 92.

The contacts I52 to H8 are arranged in a straight line group and contacts I29 and I22 are likewise arranged in an auxiliary straight line group.

The terminals may be arranged in a rectangular sliding selector instead of a rotary selector, as shown. The straight line groups would then be arranged in parallel lines instead of radial lines.

To provide low voltage operation or parallel connection of the split windings of the motor It the terminals 99, 96 and 98 are connected together by means of suitable connectors I24 and I26. The terminals 82 and H0, 92 and I09 are likewise connected into a single group by means Of Connectors I28, I30, and I3 2. Likewise termiintoasingle group bymeans of connectors I34,

.136, and E38. Alsoterminals 86,- I06,.88 and I02 are, connected. into a group: by means. of connectors- I40, I 42,-a-nd-. I44. The coilterminalsoicoil 22 are connected together asfollowsby meansof the connectorv I46: extending between contact- I I2 and H4 and connector I48-extending between terminals I'I6and IIB. :Also terminals I20 and I22 areconnected together by connector I56. In .theoperation of the device the switching mechanismis movedto .the position: shown .:in Figure. 6 to; operate the motor on 220 volts or the lowvoltage group. Assuming that-the motoriis star connected, the. neutral-point oi'the 'outer sectionof .thesplit winding will be established by means. of the connector I24 and: 26 whichcon- -nects together the contacts 94, 9t and 98 which make; connection. or. in ccntactwith contacts 62, and 66-which are; connected to theterminals 4,:5 andp-6 of themotor winding. .pLikewisei the contact: 58 which is connected to'the terminal I is in engagementwith the contact 82 and is connected by means of-connectors I28 and I30 to the contact 92 which is in engagement with thecontact 60 whichis connected to the terminallxof the-motor so thatthe terminals I and i are connected'together. .Thaterminal 2 of themetor is connected .to.contact 52 .which is in engagementzwithcontacts84 which is'connected to contact 90 bye-means ofconnectors I34 and. IE6; the. contact 90 .isinengagement with contact. 58 whichiszconneotedto=terminal 8 of the motor so that terminalsfZ andiSare connected together. Likewisatheterminal 3 oi'the motor is connected to contact-54 which is inengagement with the contact :86'whi'ch'is connected to the contact 88 by means'of'the-connectors I40 and 142, the contact-88 is in engagement with contact 58 which-is connected'to terminal 9 or the motor so that terminals 3 and 9 are connected together. It will thus be seen that this switch arrangement when in position-as shown in Figure 6 will connect together terminals4, 5 and 6, terminals I and Lterminals 2"and' 8, and terminals 3 and 9 as requiredbyfthe. N. M. A. chart. as. shown in Figure .8.

In a similar manner, the terminals Ic to-4c of the coil. 22 will be connected together as follows: Terminal I0 is connected to contact 74 which is in engagement with contact H2 'whichis connected to contact H4 which is in engagement with contact 16 which is connected to terminal 3c which is connected to the terminal 30 of the coil 22 so that terminals Ic aridSc are connected together by the connector 246. Likewise the termi-nalr2c is connected-to the'contact I8 which is in engagement with the contact !I6 which is connected to contact H8 by means of connector I48 with contact H8 being in engagement with contact I8 which is connected to terminal 40 of the coil 22 so that coil terminals 20 and 4c are connected together and the coil sections 22a and 22b are connected in parallel for low voltage operation.

To operate the dual voltage motor It on the high voltage of 440 volts the switch apparatus thrown to the position shown in Figure '7 where the terminal 4 of the motor is connected to the contact 66 of the plate 32 with the contact 66 being in engagement with contact I98 of the switch plate 34 and being connected to the contact 82 by means of the connectors I80 and I28 with contact 82 being in engagement with contact 60 which is connected to terminal I of the motor: so that terminalsfiand I areconnected together. .-Also,- the terminal 5 isconnectedto contact. 64 which is in engagement withcontact 89 and is connected tov contact by means :of connectors. I86 and I34 while the contact 84 is in engagement-withcontact 58 which is con- 'nected to'terminalv 8 of the motor so that terminals'5 and Bare connectedtogether. Likewise, terminal 6 is connected to contact 62 which is in engagement'with.contact 88 and is connected to contact 86 by means of connectors I42 and I40, the contact 86 being in engagement with contact 56 which is connected to terminal 9 of themotor so that terminals 6 and 9 are connectedtogether. Itwill thus be seen that the switch shown in the position shown in Figure 7, terminals 4ran'd "I are connected together, terminals 5 and 8 are connected together, and terminals v6 andp9are connected together .as per the N. A..chart as seen in Figure 9.

When the motor I0 is delta connected the terminals 4,5 and 6 will be disconnected from the terminals 82, 64 and-'BS-and connected as-shown in dotted lines to the auxiliary terminalsliB, I0 and 12.

In the operation of the device as a delta connected low voltage motor, the switch will be thrown to the right as shownin Figure 6 and terminals I, l and 6 willbe connected to the contacts 59, 68 and 68 which are in engagement with contacts82, 82 and I which are connected together by means of connectors I32, I30 and 28 so that terminals I, 6 and 1 are connected together. Also, terminals -3, 5 and 9 are connected to terminals-54, 56 and-I0 which are in engagementwith the contacts 86, 88 and I02 which are connectedtogether by connectors I44, I42 and I45 so that terminals-3, 5 and 9 areconnected together. Likewise, terminals 2, 8 and. 4 are connected to contacts52, 58 and" which are in engagement with contacts 64, and I 64 which areconnectcd together by connectors I38, I36 and I34 so that terminals 2, 8 and 4 .are connected together. t will thus be seenthat terminals I, I, 6, terminals.2,.5 and 9 and terminals 2, 8-and 4 .are com ected together as required by the ll..E...M.A. chart as shown in Figure 10.

For high voltage operation of the delta connected motor the handle 48 is turned to the left as shown in Fi ure? and it will .be seenthat terminal 4 is connectedto contact I2 which is in engagement with contact IIil which is connectedby. means of connector I28 to contact 82 and isin engagement with contact 60 which. is connected to terminallsc that terminalsxi and I are connected together. Also, terminal. 5 is connected to. contact 10 which is in engagement with contact I88 which is connected by means of connector I 34 to contact 04 which is in engagement with contact 58 which is connected to terminal 8 of the motor so that terminals 5 and 8 are connected together. Likewise, terminal 6 is connected to contact 68 which is in engagement with contact I86 which is in contact by means of connector I40 with contact 86 which is in engagement with contact 56 which is connected to terminal 9 of the motor so that terminals 6 and 9 are connected together. It will thus be seen that terminals 4 and l, terminals 5 and 8 and terminals 6 and 9 are connected together as per the chart according to N. M. A. standards as shown in Figure 11.

It will thus be seen that the switching device according to the present invention provides an arrangement by which a motor either delta or Y-connected may be operated at either high or low voltage by a simple changeover movement of the switch. Also, once the switch has been connected for the predetermined type of motor it will be unnecessary to ever open the terminal box and the switch may be mounted solidly thereon and be actuated as a part of the motor. The invention thus provides a simple, compact and easily operated device which may be operated without the use of skilled labor and save much time and expense in the connection of motors for operation at dual voltages.

For purposes of exemplification, a particular embodiment of the invention has been shown and described according to the best present understanding thereof, however, it will be apparent to those skilled in the art, that many changes and modifications can be made therein without departing from the true spirit of the invention.

Having thus described the invention, what is claimed as new is:

1. For use in a three phase motor of the type wherein each of the phases has a first and second coil with each of the coils having an inner and an outer end, the outer ends of said first coils being connected to the conductors of a supply line, the inner ends of said second coils being connected to determine the mode of operation of the motor, a voltage selector comprising an insulating base plate, first, second and third group of contacts mounted in said base plate, the contacts of each group being arranged in a line, said groups being equally spaced, the outer ends of said first coils being connected to said first group of contacts, the outer ends of said inner coils being connected to said second group of contacts, a fourth group of contacts, said fourth groups of contacts bein arranged intermediate said second and third group of contacts, the inner ends of said first coils being selectively connected to said third or fourth group of contacts, a switch plate slidably mounted on said base plate, means limiting motion of said switch plate with respect to said base plate, said switch plate being movable a distance equal to the distance between said first and second groups of contacts in said base plate, five groups of switch contacts in said first plate, said groups of switch contacts being spaced apart one-half the distance between the first and second groups of contacts in said base, connectors connecting the respective contacts of the first, second and third switch contacts together, connectors connecting the fourth group of switch contacts in advanced progression with respect to the contacts of the third group of switch contacts, conductors connecting the fifth group of switch contacts in short circuited relation.

2. For use in a three phase motor of the type wherein each of the phases has a first and second coil with each of the coils having an inner and an outer end, the outer ends of said first coils being connected to the conductors of a supply line, the inner ends of said second coils being connected to determine the mode of operation of the motor, a voltage selector comprising an insulating base plate, first, second and third groups of contacts mounted in said base plate, the contacts of each group being arranged in a line, said groups being equally spaced, the outer ends of said first coils being connected to said first group of contacts, the outer ends of said inner coils being connected to said second group of contacts, a fourth group of contacts, said fourth groups of contacts being arranged intermediate said second and third group of contacts, the inner ends of said first coils being selectively connected to said third or fourth group of contacts, a switch plate slidably mounted on said base plate, means limiting the motion of said switch plate with respect to said base plate, said switch plate being movable a distance equal to the distance between said first and second groups of contacts in said base plate, five groups of switch contacts in said switch plate, said groups of switch contacts being spaced apart one-half the distance between the first and second groups of contacts in said base, connectors connecting the respective contacts of the first, second and third switch contacts together, connectors connecting the fourth group of switch contacts in advanced progression with respect to the contacts of the third group of switch contacts, conductors connecting the fifth group of switch contacts in short circuited relation, a line switch for said motor, first and second magnet coils in said line switch, a group of magnet coil contacts in said base plate, two groups of magnet switch contacts in said switch plate, said groups of magnet switch contacts selectively connecting said magnet coils in series or in parallel.

HUBERT LEE KEITH.

References Cited in the file of this patent UNITED STATES PATENTS 

